The present invention relates to a vertically delivered weapon system. In particular, the invention relates to a tube for launching a rocket. The tube is extendable to a length sufficient to contain and guide the rocket while it is burning and accelerating. In its retracted position, the tube is located within a pod or multiple rocket launch housing which contains a plurality of such rockets. The pod may contain the sensors, targeting hardware and launch hardware.
In a down fired weapon delivery system, a manned or unmanned low flying aircraft ejects a rocket over a target in a manner such that it travels straight down. Simple vector analysis shows that if a vehicle carrying the rocket is moving in the forward direction and the rocket is launched rearwardly at an angle, depending upon the speed of the launched vehicle, the forward and reverse components of the rocket and vehicle cancel, yielding a downward resultant vector only. Thus, an aircraft can fly at relatively low altitudes and fire directly over the target. At high speeds, the launch can occur in a few milliseconds.
Rockets of the type herein described are launched from tubes which have a length sufficient to contain and guide the rocket while it is burning and accelerating. For example, some relatively small single and multiple warhead rockets require a launch tube as long as 36 inches in order to allow the rocket to achieve maximum acceleration and guidance. If the launch tube is pointed downward at a 155.degree. angle relative to the direction of the carrier vehicle, the tube presents a 20 inch drag surface. A pod carrying a multiplicity of such tubes represents a relatively large cross-section and contributes a large amount of drag to the vehicle at high speeds.
In order to retain the accuracy achieved by a relatively long launch tube sufficient to contain the rocket during its full burn, yet reduce the cross-section of the pod, and thereby reduce the drag, extendable telescopic tubes have been used. See for example, the patent to Madderra, Pat. No. 4,376,405, showing an extendable launch tube and locking mechanism for a launch vehicle. In Medderra, the extendable launch tube is extended by an undisclosed mechanism and locked in place. In the present invention, the launch tube is a telescopic device in which a portion of the tube is extended by the rocket and is eventually expended once the rocket is launched.